Temporal graphs and subgraphs Temporal graph G(V, E, F)with T timestamps nodes and edges keep unchanged 235 edge weights constantly and regularly vary 叫252 with timestamps -7.-2 T snapshots: G,(V, E, F1, G2(V, E, F2) GT(V,E,F density(G)=36 Temporal subgraph H(Vs, Es, Fs, i, j time interval [,jc[1,T 7,5-2 subgraph (Vs, Es of (V,E denote H(V,, Fs,i, j as G[, j] density (H)=21 ohesive density density(G) sum of eage weights among all snapshots 5Temporal graphs and subgraphs 5 Temporal graph G(V, E, F) with T timestamps • nodes and edges keep unchanged • edge weights constantly and regularly vary with timestamps • T snapshots: G1 (V, E, F1 ), G2 (V, E, F2 ), …, GT (V, E, FT) Temporal subgraph H(Vs , Es , Fs , i, j) • time interval [i, j] ⊆ [1, T] • subgraph (Vs , Es ) of (V, E) • denote H(V, E, Fs , i, j) as G[i, j] Cohesive density cdensity(G) • sum of edge weights among all snapshots cdensity(G)=36 cdensity(H)=21